Selective plug-in assembly



Nov. 29, 1966 E. J. NIELSEN 3,289,043

SELECTIVE PLUG-IN ASSEMBLY Original Filed Feb. 21, 1962 2 Sheets-Sheet OD EC) @EEJE'QHEEE] @EEIEIEIEHE Qwmghm) ACqmi EEIIEIEEEJE N ll. W1

INVENTOR.

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ATTORNEY United States Patent 3,289,043 SELECTIVE PLUG-IN ASSEMBLY Ellk J. Nielsen, Mequon, Wis, assignor to Square 1) Company, Park Ridge, Ill., a corporation of Michigan Continuation of application Ser. No. 174,878, Feb. 21, 1962. This application Apr. 6, 1965, Ser. No. 449,361 6 Claims. (Cl. 317-99) This application is a continuation of my co-pending application, Serial No. 174,878, filed February 21, 1962, now abandoned, and entitled Selective Plug-In Assembly.

This invention relates to terminal blocks and particularly to terminal blocks for selective plug-in assemblies of electrical components.

For the purposes of illustration the invention is disclosed herein for use in electrical assemblies known as NOR circuits, an example being described in the copending application of Robert C. Mierendorf, Serial No. 218, filed January 4, 1960 and entitled Electrical Assembly, now US. Patent No. 3,065,385, issued November 20, 1962.

As therein more fully described, conventional radio type components, such as resistors, capacitors, transistors, diodes, and the like, frequently employed in logic systems, have not been fully accepted in industrial practices due to the hesitancy of maintenance personnel to chance serving them. In order to overcome the psychological difficulties, the custom has grown of assembling the components and encapsulating them in settable material in a suitable assembly casing. The casing has terminal blocks whereby one terminal of each component, or group of components connected by suitable bus bars, may be connected to each other, to a source of power or to extraneous circuits, selectively, by means of push pins cooperable with sockets in the blocks.

As mentioned, the components in the casing and the inner ends of the terminal blocks and their inwardly disposed parts are embedded or encapsulated in a suitable settable plastic material which, when set, holds the components fixedly in position and prevents damage thereto and to the connect-ions therewith.

The terminal blocks have their sockets exposed at the open side of the casing. Generally the open side of the casing is closed by a plurality of terminal blocks themselves arranged in a row with their lateral faces in face to face relation, and with the open ends of sockets thereof facing outwardly at the open side of the casing. Thus, a compact assemblage or unit is provided.

The types of components, arrangements of bus bars, and the connections to be provided for between the various components are dependent largely upon the uses to which a particular assemblage is to be put, and forms no part of the present invention.

As described in the above-entitled application, each terminal block is of set plastic material, such as rubber or synthetic organic plastic. Each employs a plurality of separate inserts of conducting material, each insert extending from the outer face to the inner face of its associated block. Each insert has sockets in the form of passages which extend endwise of, and entirely through, the insert, and are open at one end within the casing and at the other end at the outside of the casing. The inserts are arranged in a row in edgewise spaced relation to each other and are embedded in the set plastic material of the blocks, leaving both ends of the passages open for reception of push pins. The open ends in the casing face inwardly thereof for access by push pins prior to placing the assemblage in the casing. The outer open ends face outwardly for access by push pins outside of the casing after the assemblage is completed.

However, there are objections to this type of prior structure. One objection is that since the passages in the inserts, which serve as sockets, are open at both ends, they have to be connected to the interior wiring by means of tapered push pins fastened onto the ends of the lead Wires to be connected thereto. Furthermore, in these structures, the material used for encapsulating the assembled components often enters the passages from the face to be exposed to the inside of the casing, particularly those passages in which no push pins are inserted prior to encapsulating. This often requires that the passages be reamed individually from their outer ends inwardly after the assembly has been otherwise completed.

Further, the taper pins used at the encapsulated side of the terminal blocks have to be soldered to their lead wires, thus adding additional expense in the manufacture of the assemblages.

In accordance with the present invention, a selective plug-in assembly of this general character is provided employing new and improved terminal blocks. Specifically, the blocks are arranged in a row in lateral face to face relation or in laterally spaced relation with spacers of insulating material therebetween, as in the above-identified copending application. Each block is of electrical insulating material and supports a row of conducting inserts arranged in edge to edge spaced relation. Each insert is of electrical con-ducting material, has one end accessible from the outside of the casing, and a pair of sockets extending from its outer end part way of the length of the insert toward its inner end. The sockets are closed at their inner end. Each insert is provided at its inner end with a notch which is open both through the inner end and through the side face of the insert from the inner end part way toward the outer end of the insert. The notch is readily accessible for receiving a terminal lead and is Well adapted for soldering of the terminal lead in place therein. The notch is uncommunicated with the sockets of its insert. Accordingly, the encapsulating material applied at the inner ends of the terminal blocks cannot enter the sockets of the inserts. While the inserts may be secured in a row in spaced relation to each other in the blocks by molding of settable plastic material thereabout, preferably the blocks are preformed with a plurality of passages in which the inserts may subsequently be introduced individually, and by the walls of which the inserts are held firmly in position in lateral edgewise spaced, and electrically insulated, relation with respect to each other.

Each insert has two sockets so that a plurality of extraneous terminal leads can be connected together therethrough and to the same terminal of the insert.

Furthermore, if desired, the inner ends of some of the inserts may be connected together so as to supply as many sockets as desired for connection to a specific one of the terminals of selected ones of the electrical components or circuits.

The components with the terminal blocks, after soldering the leads of the components into the notches of the inserts, may be assembled and encapsulated in a manner described in the above-entitled application. The specific advantages of the structure reside in the ease and economy of assembly and manufacture, particularly the connection of leads to the inserts and the elimination of fouling of the sockets by the encapsulating material.

Various other objects and advantages will become apparent from the following description, wherein reference is made to the drawings, in which:

FIG. 1 is a top plan view of an assembly embodying the principles of the present invention;

FIG. 2 is a front elevation of the assembly illustrated in FIG. 1, part thereof being shown in section for clearness in illustration;

FIG. 3 is a side elevation of a terminal block showing a number of terminal leads of an internal circuit connected thereto;

FIG. 4 is an end elevation of an assembly of terminal blocks and electrical components connected thereto, prior to encapsulation thereof;

FIG. 5 is a right hand elevation of the blocks and components illustrated in FIG. 4;

FIG. 6 is an enlarged top plan view of one of the terminal blocks of the present invention, before installation of its inserts;

FIG. 7 is a bottom plan view of the block of FIG. 6;

FIG. 8 is a vertical cross sectional view taken on the line 88 in FIG. 6;

FIG. 9 is a vertical longitudinal sectional view taken on the line 99 in FIG. 8;

FIG. 10 is a top plan view of one of the inserts used in the present invention;

FIG. 11 is a bottom plan view of the insert illustrated in FIG. 10;

FIG. 12 is a front elevation of the insert illustrated in FIG. 10, part thereof being shown in section for clearness in illustration;

FIG. 13 is a vertical cross sectional view taken on the line 1313 in FIG. 12;

FIG. 14 is a left side elevation of the insert illustrated in FIG. 12; and

FIG. 15 is an enlarged fragmentary vertical sectional view through a portion of the terminal blocks with an insert mounted therein, showing the manner of the connection of the leads and push pins thereto.

Referring to the drawings, the assembly is shown as contained in the casing or container 1 closed at the top by a row of terminal blocks 2 with spacers 3 filling the spaces therebetween. The assembly is held in the casing 1 by a suitable rim 4 bolted in place on the open end of the casing, or otherwise.

Referring to FIGS. 3, 4 and 5, the assembly includes bus bars 6 and 7, which may run in various directions depending on the connection desired. Leads, some of which are indicated at 9, 10 and 11, respectively, are connected to the selected bus bars and to electric components of the assembly, some of which components are indicated at 12, 13 and 14, respectively.

Terminal leads 15, 16 and 17 extend from components 12, 13 and 14, respectively, and are connected to the terminal blocks 2, as will later be explained. Large numbers of small components may be thus secured to terminals and to the blocks preparatory to encapsulation.

Referring next to the blocks 2, each block comprises a support, indicated generally at 20, preferably in the shape of a rectangular parallelepiped, composed of premolded set synthetic, organic, plastic material having good impact, heat resisting and insulating qualities.

Each block is provided with a plurality of passages 21 extending therethrough from one edge to the opposite edge. The passages 21 are arranged in parallel relation to each other in a row in edgewise spaced relation and are separated edgewise from each other by the insulating material of which the block 2% is composed. Each of the passages 21 may be slightly flared at its outer or entrance end 22. Each has parallel side walls 23 which extend from the entrance end to the opposite end of the passage at the inner edge of the block 20. Each passage has edge walls 24 which extend from its entrance end to the opposite end, and are parallel part way of their length. Beginning part way toward the opposite end of each passage the walls 24 converge, as indicated at 2401, to said opposite end. Ribs 25 are provided on the walls 24 and extend from the entrance end of the passage 21 to the juncture of the parallel portions of the walls 24- and the Wall portions 24a. The ribs 25 are of various lengths. In the form illustrated, they are about of an inch long and about 0.03 of an inch in width and depth.

Inserts 30, of sintered metal powder, for example, such as a sintered bronze powder, are provided for insertion in the passages 21. Each insert is shaped to fit snugly in one of the passages 21 with its sides and edges in juxtaposition with those of its passages 21. The ribs 25 can be distorted by an insert as it is pressed into place in a passage 21 so that the edges of the insert can engage the edge walls 24 and 24a of the associated passage 21 by the elastic deformation of the ribs 25. When the inserts are installed they are held securely in place. If desired, they may be secured more firmly by suitable solvent or plastic cement.

In the form illustrated, each insert 30 is in generally rectangular cross section, having parallel side Walls 31. The insert has edge walls 32 which extend part way of the length of the insert from one end in parallelism with each other. At the ends of the parallel portions the edge walls converge downwardly, as indicated at 33, to the opposite end of the insert. Each insert is shaped relative to its passage so that it can be press fitted into the passage, tapered and foremost, so that the inner end of the insert projects beyond the inner edge of the associated block 20.

Each insert is provided with a pair of sockets 35. These sockets are open at the outer end of the insert and block, and taper gradually part way of the length toward the opposite or inner end of the insert, as indicated at 36. They may be of constant diameter, as indicated at 37, for the remainder of their length. The lower ends of these sockets are closed so that encapsulating material applied under pressure to the inner ends of the insert, or inner edge of the terminal blocks 20, cannot pass through the insert in any manner and enter into the sockets.

Each insert is provided with a connecting groove or notch 33. The notch 38 extends from the location about midway between the ends of the insert entirely to the inner tapered end and is open at the inner end of the insert, as indicated at 39. The notch also is open, for substantially its full length, as indicated at 40, at one face of the insert. Consequently, one or more terminal leads can readily be inserted in the groove from the side face of the insert and solder applied for soldering it firmly in place in the groove.

As illustrated in FIG. 15, the loWer ends of each insert extend beyond the inner edge of the terminal block 2 so that the notches are accessible for receiving the terminal wires even after the inserts are inserted in the block. However, if desired, terminal wires can be installed by passing them through the passages 21 from the tapered inner end until they protrude from the outer end, then soldering them into the notches 38, then pressing the inserts back into the passages 21 tape-red end foremost. The manner of installation depends upon the particular requirements. The arrangement of the terminals of the components relative to each other and to the inserts depends upon the intended use of the assembly. For instance, a component may have one terminal connected to one insert and another terminal connected to another insert. Again, a number of the terminals may be connected to a common bus bar. On the other hand, some of the components may have terminals connected to bus bars to be encapsulated and one terminal connected to one of the insert or a plurality of leads from one terminal may be connected to a plurality of inserts. These arrangements depend upon the different possible connections contemplated.

The terminal blocks 3, being of insulating material, insulate the inserts from each other unless they are pur posely connected by wires. The blocks 3 are placed in face to face relation with insulating spacers therebetween, as desired, and they and the spacers may be cemented together, or they may be held in assembled relation otherwise.

Their inner edges are exposed toward the components, and all of the components and their connections with each other and with the inserts are encapsulated in the material selected, after which the assembled components and terminal blocks are mounted in the casing 1.

External circuits to be connected to the sockets include terminal leads which are provided with conventional push pins, such as described in the above application and indicated herein at 41 in FIG. 4. The pins fit with a snug yieldable fit in the sockets 35, respectively.

Inasmuch as the terminal blocks 3 and the inserts are separately made and then assembled, none of the plastic material enters the sockets. Furthermore, since the notches 38 do not connect with the sockets, encapsulating material applied to the inner ends of the bars and inserts cannot reach the sockets. Furthermore, if the encapsulating material is injected under pressure into the casing 1 after the blocks are mounted in place in the open side thereof, none of the encapsulating material can reach the sockets 35.

It is apparent, therefore, that with this arrangement, a much improved terminal board and insert combination which overcomes the objections hereinbefore discussed is provided.

Having thus described my invention, I claim:

1. A selective plug-in assembly of electrical compopents and comprising a casing having an open side, a plurality of electrical components in the casing, a support of relatively rigid insulating material and having an outer face and an inner face, and having a plurality of I separate passages extending therethrough from the outer to the inner face and arranged side by side, connecting means securing the support to the casing in closing relation to the open side of the casing with the inner face of the support exposed within the casing, conducting inserts secured in the passages, respectively, and electrically insulated from each other by the walls of the passages, each insert having an outer end exposed for access at said outer face and an inner end portion exposed for access at said inner face, and each insert having at least one pin-received socket which is open at the outer end of the insert and is closed at its inner end and extends inwardly toward the inner end of the insert and terminates in spaced relation to the inner end of the insert, at least some of the inserts having cavities, respectively, in their inner end portions and uncommunicated with their sockets, each of said cavities accommodating the end of a component terminal wire soldered in place in the associated cavity, encapsulating plastic material in set condition in the casing in embedding relation to, and bonded to, the components, and to inner end portions of the inserts, each passage having a portion with a cross section which, beginning at a location in spaced relation to the outer and inner faces, is progressively reduced in a direction toward the inner face, and each insert having a portion correspondingly progressively reduced and fitting said portion of the passage, and said insert and passage being of substantially uniform cross section from the outer face of the support to said location.

2. The structure according to claim 1 wherein said support is preformed with said passages therein, said inserts are insertable into said passages endwise from the outer face of the support, a slight rib is provided on at least one inner wall of each passage between the outer end of the passage and the inner end of said portion of the passage, said rib extends endwise in a direction from the outer end toward the inner end of the associated passage, and said rib is elastically compressible in a direction normal to its associated side wall by the associated insert during insertion of the insert.

3. The structure according to claim 1 wherein each cavity is in the form of a notch which is open through the inner end of the insert and from said inner end along one side face of the inner end portion of the insert for admitting molten solder therethrough into the notch while a component terminal wire is in the notch.

4. The structure according to claim 1 wherein the support comprises a plurality of terminal blocks secured on the same casing in a row in lateral face to face spaced relation, spacers fill the spaces between the blocks, and the blocks and spacers together close the open side of the casing.

5. A selective plug-in assembly of electrical components comprising: a casing having an open side, a plurality of electrical components in the casing, a support of relatively rigid insulating material having an outer face, an inner face, and a plurality of separate passages extending therethrough from the outer to the inner face and arranged side by side, means positioning the support on the casing in closing relation to the open side of the casing with the inner face of the support exposed Within the casing, conducting inserts secured in each of the passages electrically insulated from each other by the walls of the passages, each insert having an outer end exposed for access at said outer face and an inner end portion exposed for access at said inner face, and each insert having at least one pin-receiving socket which is open at the outer end and is closed at its inner end and extends inwardly toward the inner end of the insert and terminates in spaced relation to the inner end of the insert, a cavity in the inner end of each of said inserts uncommunicated with the sockets in the respective inserts, each of said cavities providing a solder well for accommodating the end of a component terminal wire soldered in place in the associated cavity, encapsulating plastic material in set condition in the casing embedding and bonded to the components within the casing, each passage in the support having a portion with a cross section which, beginning at a location in spaced relation to the outer and inner faces is progressively reduced in a direction toward the inner face to provide a tapered portion in each passage, and each insert having a portion correspondingly progressively reduced to provide a tapered portion which is snugly titted with the tapered portion of the passage, and said insert and passage being of substantially equal and uniform cross section from the outer face of the support to said location.

6. The combination as recited in claim 5 wherein each conducting insert has a pair of pin receiving sockets which are tapered to receive a tapered pin.

References Cited by the Examiner UNITED STATES PATENTS 2,874,313 2/1959 Githens 339-18 X 3,065,385 11/1965 Mierendorf 317-401 ROBERT K. SCHAEFER, Primary Examiner. 

1. A SELECTIVE PLUG-IN ASSEMBLY OF ELECTRICAL COMPOPENTS AND COMPRISING A CASING HAVING AN OPEN SIDE, A PLURALITY OF ELECTRICAL COMPONENTS IN THE CASING, A SUPPORT OF RELATIVELY RIGID INSULATING MATERIAL AND HAVING AN OUTER FACE AND AN INNER FACE, AND HAVING A PLURALITY OF SEPARATE PASSAGES EXTENDING THERETHROUGH FROM THE OUTER TO THE INNER FACE AND ARRANGED SIDE BY SIDE, CONNECTING MEANS SECURING THE SUPPORT TO THE CASING IN CLOSING RELATION TO THE OPEN SIDE OF THE CASING WITH THE INNER FACE OF THE SUPPORT EXPOSED WITHIN THE CASING, CONDUCTING INSERTS SECURED IN THE PASSAGES, RESPECTIVELY, AND ELECTRICALLY INSULATED FROM EACH OTHER BY THE WALLS OF THE PASSAGES, EACH INSERT HAVING AN OUTER END EXPOSED FOR ACCESS AT SAID OUTER FACE AND AN INNER END PORTION EXPOSED FOR ACCESS AT SAID INNER FACE, AND EACH INSERT HAVING AT LEAST ONE PIN-RECEIVED SOCKET WHICH IS OPEN AT THE OUTER END OF THE INSERT AND IS CLOSED AT ITS INNER END AND EXTENDS INWARDLY TOWARD THE INNER END OF THE INSERT AND TERMINATES IN SPACED RELATION TO THE INNER END OF THE INSERT, AT LEAST SOME OF THE INSERT HAVING CAVITIES, RESPECTIVELY, IN THEIR INNER END PORTIONS AND UNCOMMUNICATED WITH THEIR SOCKETS, EACH OF SAID CAVITIES ACCOMMODATING THE END OF A COMPONENT TERMINAL WIRE SOLDERED IN PLACE IN THE ASSOCIATED CAVITY, ENCAPSULATING PLASTIC MATERIAL IN SET CONDITION IN THE CASING IN EMBEDDING RELATION TO, AND BONDED TO, THE COMPONENTS, AND TO INNER END PORTIONS OF THE INSERTS, EACH PASSAGE HAVING A PORTION WITH A CROSS SECTION WHICH, BEGINNING AT A LOCATION IN SPACED RELATION TO THE OUTER AND INNER FACES, IS PROGRESSIVELY REDUCED IN A DIRECTION TOWARD THE INNER FACE, AND EACH INSERT HAVING A PORTION CORRESPONDINGLY PROGRESSIVELY REDUCED AND FITTING SAID PORTION OF THE PASSAGE, AND SAID INSERT AND PASSAGE BEING OF SUBSTANTIALLY UNIFORM CROSS SECTION FROM THE OUTER FACE OF THE SUPPORT TO SAID LOCATION. 